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package hostos
import (
"context"
"errors"
"os"
"time"
)
const (
lockRetryMin = 10 * time.Millisecond
lockRetryMax = 500 * time.Millisecond
)
var ErrLockHeld = errors.New("hostos: the lock stayed held")
func LockWait(ctx context.Context, f *os.File, how int, wait time.Duration) error {
ctx, cancel := context.WithTimeout(ctx, wait)
defer cancel()
delay := lockRetryMin
for {
err := Lock(f, how|LockNonBlocking)
if err == nil {
return nil
}
t := time.NewTimer(delay)
select {
case <-ctx.Done():
t.Stop()
if errors.Is(ctx.Err(), context.DeadlineExceeded) {
return errors.Join(ErrLockHeld, err)
}
return errors.Join(ctx.Err(), err)
case <-t.C:
}
delay = min(delay*2, lockRetryMax)
}
}
